There are lots of reason sometime calls not get connect and return with a error code to disconnect – those are normal and error codes are same for almost all softswitch. Sometime direct vendors or wholesaler want error code replacement due to increase call connectivity quality – like when some call termination reason come “Not Found” then call get disconnected but carrier want it to try secondary routes if that works. In that case they want some replacement error cose where call do not get disconnect and try next gateway or routes. All clients not like this because some want accurate error codes. So who need to change error code to other code like “service unavailable” (503) then you can follow below screenshot.
Its not that hard but handy – if you have any more question for vos3000 commectivity issues then please knock me at whatsapp – +8801911119966